Related Clues:

• Sand component
• Glassmaking material
• Flint, e.g.
• Quartz or flint
• Glass-making mixture
• Agate mineral
• Quartz, e.g.
• Sand stuff
• Stuff in those packets you're not supposed to eat
• Pottery glaze base
• Quartz component
• It's used in making glass
• Sand, essentially
• Glassmaker's mixture
• Quartz compound